15 PLD/FPGA Commands

Programmable Logic Devices (PLDs) and the more flexible Field Programmable Gate Arrays (FPGAs) are both types of programmable hardware. OpenOCD can support programming them. Although PLDs are generally restrictive (cells are less functional, and there are no special purpose cells for memory or computational tasks), they share the same OpenOCD infrastructure. Accordingly, both are called PLDs here.

15.1 PLD/FPGA Configuration and Commands

As it does for JTAG TAPs, debug targets, and flash chips (both NOR and NAND), OpenOCD maintains a list of PLDs available for use in various commands. Also, each such PLD requires a driver.

They are referenced by the number shown by the pld devices command, and new PLDs are defined by pld device driver_name.

Config Command: pld device driver_name tap_name [driver_options]

Defines a new PLD device, supported by driver driver_name, using the TAP named tap_name. The driver may make use of any driver_options to configure its behavior.

Command: pld devices

Lists the PLDs and their numbers.

Command: pld load num filename

Loads the file filename into the PLD identified by num. The file format must be inferred by the driver.

15.2 PLD/FPGA Drivers, Options, and Commands

Drivers may support PLD-specific options to the pld device definition command, and may also define commands usable only with that particular type of PLD.

FPGA Driver: virtex2

Virtex-II is a family of FPGAs sold by Xilinx. It supports the IEEE 1532 standard for In-System Configuration (ISC). No driver-specific PLD definition options are used, and one driver-specific command is defined.

Command: virtex2 read_stat num

Reads and displays the Virtex-II status register (STAT) for FPGA num.